"Mitrokhin has sent the first complaint to CEC chairman Vladimir Churov and Prosecutor General Yury Chaika demanding a probe into irregularities identified by Yabloko monitors and candidates in elections in 11 constituent territories," a Yabloko press release obtained by Interfax on Sunday says.

The complaint lists the worst irregularities at 28 polling stations: ballot-stuffing, 'merry-go-rounds', the removal of monitors, and the bribery of voters in regional elections in Krasnodar territory and in municipal elections in Primorye and Altai territories, and in Bryansk, Ryazan, Irkutsk, Saratov, Tula, Moscow and Yaroslavl regions.

"In addition, the document says that observers from independent candidates and parties were barred from over half of the polling's stations in Tatarstan on the pretext of the absence of stamps on their assignments," the press release says.

"The Yabloko leader demands that CEC and prosecutors check the reports and hold the culprits responsible, if the information proves true," the press release says.